Lasers and other such devices are used in various surgical procedures for therapeutically treating tissue, such as skin tissue. For example, medical lasers are used to treat naturally occurring skin lesions and discolorations including freckles, age spots, birth marks, melanomas, nevi, and lentigines. Lasers are also used to remove other visible skin features such as tattoos and "port wine" stain birth marks which are caused by a plurality of enlarged blood vessels. A patient may choose to have such skin features treated for cosmetic reasons and/or medical necessity.
Generally a medical laser for use in treating skin tissue has a handpiece adapted for manipulation by an operator. The handpiece is coupled to a source of laser energy by a cable that can have an optical fiber for carrying the laser energy to the handpiece. The handpiece is guided to a predetermined distance from the treatment area, i.e., skin surface, by a distance gauge or standoff. For example, U.S. Pat. No. 5,217,455 discloses a method for treating skin tissue with laser energy emitted from a medical laser handpiece having a distance gauge that is placed against the skin to focus the laser energy to a chosen treatment area. The distance gauge is a rod-like member extending from a distal end of the handpiece. U.S. Pat. No. 5,454,807 discloses a catheter-type laser energy delivery system for treating tissue. The catheter used with such a system includes a distal tip assembly having a body with an optical fiber disposed therein. An adjustable standoff extends from alongside the body to maintain a proper distance from the end of the optical fiber and the surface of the tissue to be treated. The above-cited references are incorporated by reference herein.
To treat a portion of skin, a suitably trained operator positions the handpiece in a desired location with the standoff placed in contact with the skin of a patient. The standoff maintains a predetermined distance between the handpiece and the skin surface. The operator activates the handpiece to energize a desired tissue area. As the laser energy contacts skin tissue, debris in the form of energized skin tissue is projected away from the treatment site. This tissue debris can be propelled to the energy-emitting end of the optical fiber thereby distorting and/or blocking the flow of laser energy to the treatment area.
It would be desirable to provide a system for focusing energy to a desired treatment site, while also protecting a energy delivery handpiece from tissue debris emanating from the treatment site.